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darling-objc4/runtime/objc-class-old.mm
Thomas A 5a22f74c04 Fix Building For i386/Non-OBJC2
2022-04-29 10:13:27 -07:00

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/*
* Copyright (c) 1999-2009 Apple Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/***********************************************************************
* objc-class-old.m
* Support for old-ABI classes, methods, and categories.
**********************************************************************/
#if !__OBJC2__
#include "objc-private.h"
#include "objc-runtime-old.h"
#include "objc-file-old.h"
#include "objc-cache-old.h"
static Method _class_getMethod(Class cls, SEL sel);
static Method _class_getMethodNoSuper(Class cls, SEL sel);
static Method _class_getMethodNoSuper_nolock(Class cls, SEL sel);
static Class _class_getNonMetaClass(Class cls, id obj);
static void flush_caches(Class cls, bool flush_meta);
// Freed objects have their isa set to point to this dummy class.
// This avoids the need to check for Nil classes in the messenger.
static const void* freedObjectClass[12] =
{
Nil, // isa
Nil, // superclass
"FREED(id)", // name
0, // version
0, // info
0, // instance_size
nil, // ivars
nil, // methodLists
(Cache) &_objc_empty_cache, // cache
nil, // protocols
nil, // ivar_layout;
nil // ext
};
/***********************************************************************
* _class_getFreedObjectClass. Return a pointer to the dummy freed
* object class. Freed objects get their isa pointers replaced with
* a pointer to the freedObjectClass, so that we can catch usages of
* the freed object.
**********************************************************************/
static Class _class_getFreedObjectClass(void)
{
return (Class)freedObjectClass;
}
/***********************************************************************
* _objc_getFreedObjectClass. Return a pointer to the dummy freed
* object class. Freed objects get their isa pointers replaced with
* a pointer to the freedObjectClass, so that we can catch usages of
* the freed object.
**********************************************************************/
Class _objc_getFreedObjectClass(void)
{
return _class_getFreedObjectClass();
}
static void allocateExt(Class cls)
{
if (! (cls->info & CLS_EXT)) {
_objc_inform("class '%s' needs to be recompiled", cls->name);
return;
}
if (!cls->ext) {
uint32_t size = (uint32_t)sizeof(old_class_ext);
cls->ext = (old_class_ext *)calloc(size, 1);
cls->ext->size = size;
}
}
static inline old_method *_findNamedMethodInList(old_method_list * mlist, const char *meth_name) {
int i;
if (!mlist) return nil;
for (i = 0; i < mlist->method_count; i++) {
old_method *m = &mlist->method_list[i];
if (0 == strcmp((const char *)(m->method_name), meth_name)) {
return m;
}
}
return nil;
}
/***********************************************************************
* Method list fixup markers.
* mlist->obsolete == fixed_up_method_list marks method lists with real SELs
* versus method lists with un-uniqued char*.
* PREOPTIMIZED VERSION:
* Fixed-up method lists get mlist->obsolete == OBJC_FIXED_UP
* dyld shared cache sets this for method lists it preoptimizes.
* UN-PREOPTIMIZED VERSION
* Fixed-up method lists get mlist->obsolete == OBJC_FIXED_UP_outside_dyld
* dyld shared cache uses OBJC_FIXED_UP, but those aren't trusted.
**********************************************************************/
#define OBJC_FIXED_UP ((void *)1771)
#define OBJC_FIXED_UP_outside_dyld ((void *)1773)
static void *fixed_up_method_list = OBJC_FIXED_UP;
// sel_init() decided that selectors in the dyld shared cache are untrustworthy
void disableSharedCacheOptimizations(void)
{
fixed_up_method_list = OBJC_FIXED_UP_outside_dyld;
}
/***********************************************************************
* fixupSelectorsInMethodList
* Uniques selectors in the given method list.
* The given method list must be non-nil and not already fixed-up.
* If the class was loaded from a bundle:
* fixes up the given list in place with heap-allocated selector strings
* If the class was not from a bundle:
* allocates a copy of the method list, fixes up the copy, and returns
* the copy. The given list is unmodified.
*
* If cls is already in use, methodListLock must be held by the caller.
**********************************************************************/
static old_method_list *fixupSelectorsInMethodList(Class cls, old_method_list *mlist)
{
int i;
size_t size;
old_method *method;
old_method_list *old_mlist;
if ( ! mlist ) return nil;
if ( mlist->obsolete == fixed_up_method_list ) {
// method list OK
} else {
bool isBundle = cls->info & CLS_FROM_BUNDLE;
if (!isBundle) {
old_mlist = mlist;
size = sizeof(old_method_list) - sizeof(old_method) + old_mlist->method_count * sizeof(old_method);
mlist = (old_method_list *)malloc(size);
memmove(mlist, old_mlist, size);
} else {
// Mach-O bundles are fixed up in place.
// This prevents leaks when a bundle is unloaded.
}
mutex_locker_t lock(selLock);
for ( i = 0; i < mlist->method_count; i += 1 ) {
method = &mlist->method_list[i];
method->method_name =
sel_registerNameNoLock((const char *)method->method_name, isBundle); // Always copy selector data from bundles.
}
mlist->obsolete = fixed_up_method_list;
}
return mlist;
}
/***********************************************************************
* nextMethodList
* Returns successive method lists from the given class.
* Method lists are returned in method search order (i.e. highest-priority
* implementations first).
* All necessary method list fixups are performed, so the
* returned method list is fully-constructed.
*
* If cls is already in use, methodListLock must be held by the caller.
* For full thread-safety, methodListLock must be continuously held by the
* caller across all calls to nextMethodList(). If the lock is released,
* the bad results listed in class_nextMethodList() may occur.
*
* void *iterator = nil;
* old_method_list *mlist;
* mutex_locker_t lock(methodListLock);
* while ((mlist = nextMethodList(cls, &iterator))) {
* // do something with mlist
* }
**********************************************************************/
static old_method_list *nextMethodList(Class cls,
void **it)
{
uintptr_t index = *(uintptr_t *)it;
old_method_list **resultp;
if (index == 0) {
// First call to nextMethodList.
if (!cls->methodLists) {
resultp = nil;
} else if (cls->info & CLS_NO_METHOD_ARRAY) {
resultp = (old_method_list **)&cls->methodLists;
} else {
resultp = &cls->methodLists[0];
if (!*resultp || *resultp == END_OF_METHODS_LIST) {
resultp = nil;
}
}
} else {
// Subsequent call to nextMethodList.
if (!cls->methodLists) {
resultp = nil;
} else if (cls->info & CLS_NO_METHOD_ARRAY) {
resultp = nil;
} else {
resultp = &cls->methodLists[index];
if (!*resultp || *resultp == END_OF_METHODS_LIST) {
resultp = nil;
}
}
}
// resultp now is nil, meaning there are no more method lists,
// OR the address of the method list pointer to fix up and return.
if (resultp) {
if (*resultp) {
*resultp = fixupSelectorsInMethodList(cls, *resultp);
}
*it = (void *)(index + 1);
return *resultp;
} else {
*it = 0;
return nil;
}
}
/* These next three functions are the heart of ObjC method lookup.
* If the class is currently in use, methodListLock must be held by the caller.
*/
static inline old_method *_findMethodInList(old_method_list * mlist, SEL sel) {
int i;
if (!mlist) return nil;
for (i = 0; i < mlist->method_count; i++) {
old_method *m = &mlist->method_list[i];
if (m->method_name == sel) {
return m;
}
}
return nil;
}
static inline old_method * _findMethodInClass(Class cls, SEL sel) __attribute__((always_inline));
static inline old_method * _findMethodInClass(Class cls, SEL sel) {
// Flattened version of nextMethodList(). The optimizer doesn't
// do a good job with hoisting the conditionals out of the loop.
// Conceptually, this looks like:
// while ((mlist = nextMethodList(cls, &iterator))) {
// old_method *m = _findMethodInList(mlist, sel);
// if (m) return m;
// }
if (!cls->methodLists) {
// No method lists.
return nil;
}
else if (cls->info & CLS_NO_METHOD_ARRAY) {
// One method list.
old_method_list **mlistp;
mlistp = (old_method_list **)&cls->methodLists;
*mlistp = fixupSelectorsInMethodList(cls, *mlistp);
return _findMethodInList(*mlistp, sel);
}
else {
// Multiple method lists.
old_method_list **mlistp;
for (mlistp = cls->methodLists;
*mlistp != nil && *mlistp != END_OF_METHODS_LIST;
mlistp++)
{
old_method *m;
*mlistp = fixupSelectorsInMethodList(cls, *mlistp);
m = _findMethodInList(*mlistp, sel);
if (m) return m;
}
return nil;
}
}
static inline old_method * _getMethod(Class cls, SEL sel) {
for (; cls; cls = cls->superclass) {
old_method *m;
m = _findMethodInClass(cls, sel);
if (m) return m;
}
return nil;
}
// called by a debugging check in _objc_insertMethods
IMP findIMPInClass(Class cls, SEL sel)
{
old_method *m = _findMethodInClass(cls, sel);
if (m) return m->method_imp;
else return nil;
}
/***********************************************************************
* _freedHandler.
**********************************************************************/
static void _freedHandler(id obj, SEL sel)
{
__objc_error (obj, "message %s sent to freed object=%p",
sel_getName(sel), (void*)obj);
}
/***********************************************************************
* _class_resolveClassMethod
* Call +resolveClassMethod, looking for a method to be added to class cls.
* cls should be a metaclass.
* Does not check if the method already exists.
**********************************************************************/
static void _class_resolveClassMethod(id inst, SEL sel, Class cls)
{
ASSERT(cls->isMetaClass());
SEL resolve_sel = @selector(resolveClassMethod:);
#if defined(DARLING) && defined(__i386__)
if (!lookUpImpOrNil(inst, resolve_sel, cls)) {
#else
if (!lookUpImpOrNilTryCache(inst, resolve_sel, cls)) {
#endif
// Resolver not implemented.
return;
}
BOOL (*msg)(Class, SEL, SEL) = (typeof(msg))objc_msgSend;
bool resolved = msg(_class_getNonMetaClass(cls, inst), resolve_sel, sel);
// Cache the result (good or bad) so the resolver doesn't fire next time.
// +resolveClassMethod adds to self->ISA() a.k.a. cls
#if defined(DARLING) && defined(__i386__)
IMP imp = lookUpImpOrNil(inst, sel, cls);
#else
IMP imp = lookUpImpOrNilTryCache(inst, sel, cls);
#endif
if (resolved && PrintResolving) {
if (imp) {
_objc_inform("RESOLVE: method %c[%s %s] "
"dynamically resolved to %p",
cls->isMetaClass() ? '+' : '-',
cls->nameForLogging(), sel_getName(sel), imp);
}
else {
// Method resolver didn't add anything?
_objc_inform("RESOLVE: +[%s resolveClassMethod:%s] returned YES"
", but no new implementation of %c[%s %s] was found",
cls->nameForLogging(), sel_getName(sel),
cls->isMetaClass() ? '+' : '-',
cls->nameForLogging(), sel_getName(sel));
}
}
}
/***********************************************************************
* _class_resolveInstanceMethod
* Call +resolveInstanceMethod, looking for a method to be added to class cls.
* cls may be a metaclass or a non-meta class.
* Does not check if the method already exists.
**********************************************************************/
static void _class_resolveInstanceMethod(id inst, SEL sel, Class cls)
{
SEL resolve_sel = @selector(resolveInstanceMethod:);
#if defined(DARLING) && defined(__i386__)
if (! lookUpImpOrNil(cls, resolve_sel, cls->ISA())) {
#else
if (! lookUpImpOrNilTryCache(cls, resolve_sel, cls->ISA())) {
#endif
// Resolver not implemented.
return;
}
BOOL (*msg)(Class, SEL, SEL) = (typeof(msg))objc_msgSend;
bool resolved = msg(cls, resolve_sel, sel);
// Cache the result (good or bad) so the resolver doesn't fire next time.
// +resolveInstanceMethod adds to self a.k.a. cls
#if defined(DARLING) && defined(__i386__)
IMP imp = lookUpImpOrNil(inst, sel, cls);
#else
IMP imp = lookUpImpOrNilTryCache(inst, sel, cls);
#endif
if (resolved && PrintResolving) {
if (imp) {
_objc_inform("RESOLVE: method %c[%s %s] "
"dynamically resolved to %p",
cls->isMetaClass() ? '+' : '-',
cls->nameForLogging(), sel_getName(sel), imp);
}
else {
// Method resolver didn't add anything?
_objc_inform("RESOLVE: +[%s resolveInstanceMethod:%s] returned YES"
", but no new implementation of %c[%s %s] was found",
cls->nameForLogging(), sel_getName(sel),
cls->isMetaClass() ? '+' : '-',
cls->nameForLogging(), sel_getName(sel));
}
}
}
/***********************************************************************
* _class_resolveMethod
* Call +resolveClassMethod or +resolveInstanceMethod.
* Returns nothing; any result would be potentially out-of-date already.
* Does not check if the method already exists.
**********************************************************************/
static void
_class_resolveMethod(id inst, SEL sel, Class cls)
{
if (! cls->isMetaClass()) {
// try [cls resolveInstanceMethod:sel]
_class_resolveInstanceMethod(inst, sel, cls);
}
else {
// try [nonMetaClass resolveClassMethod:sel]
// and [cls resolveInstanceMethod:sel]
_class_resolveClassMethod(inst, sel, cls);
#if defined(DARLING) && defined(__i386__)
if (!lookUpImpOrNil(inst, sel, cls)) {
#else
if (!lookUpImpOrNilTryCache(inst, sel, cls)) {
#endif
_class_resolveInstanceMethod(inst, sel, cls);
}
}
}
/***********************************************************************
* log_and_fill_cache
* Log this method call. If the logger permits it, fill the method cache.
* cls is the method whose cache should be filled.
* implementer is the class that owns the implementation in question.
**********************************************************************/
static void
log_and_fill_cache(Class cls, Class implementer, Method meth, SEL sel)
{
#if SUPPORT_MESSAGE_LOGGING
if (objcMsgLogEnabled) {
bool cacheIt = logMessageSend(implementer->isMetaClass(),
cls->nameForLogging(),
implementer->nameForLogging(),
sel);
if (!cacheIt) return;
}
#endif
_cache_fill (cls, meth, sel);
}
/***********************************************************************
* lookUpImpOrForward.
* The standard IMP lookup.
* Without LOOKUP_INITIALIZE: tries to avoid +initialize (but sometimes fails)
* Without LOOKUP_CACHE: skips optimistic unlocked lookup (but uses cache elsewhere)
* Most callers should use LOOKUP_INITIALIZE and LOOKUP_CACHE
* inst is an instance of cls or a subclass thereof, or nil if none is known.
* If cls is an un-initialized metaclass then a non-nil inst is faster.
* May return _objc_msgForward_impcache. IMPs destined for external use
* must be converted to _objc_msgForward or _objc_msgForward_stret.
* If you don't want forwarding at all, use LOOKUP_NIL.
**********************************************************************/
IMP lookUpImpOrForward(id inst, SEL sel, Class cls, int behavior)
{
Class curClass;
IMP methodPC = nil;
Method meth;
bool triedResolver = NO;
methodListLock.assertUnlocked();
// Optimistic cache lookup
#ifdef DARLING
if ((behavior & LOOKUP_NOCACHE) == 0) {
#else
if (behavior & LOOKUP_CACHE) {
#endif
methodPC = _cache_getImp(cls, sel);
if (methodPC) goto out_nolock;
}
// Check for freed class
if (cls == _class_getFreedObjectClass())
return (IMP) _freedHandler;
// Check for +initialize
if ((behavior & LOOKUP_INITIALIZE) && !cls->isInitialized()) {
initializeNonMetaClass (_class_getNonMetaClass(cls, inst));
// If sel == initialize, initializeNonMetaClass will send +initialize
// and then the messenger will send +initialize again after this
// procedure finishes. Of course, if this is not being called
// from the messenger then it won't happen. 2778172
}
// The lock is held to make method-lookup + cache-fill atomic
// with respect to method addition. Otherwise, a category could
// be added but ignored indefinitely because the cache was re-filled
// with the old value after the cache flush on behalf of the category.
retry:
methodListLock.lock();
// Try this class's cache.
methodPC = _cache_getImp(cls, sel);
if (methodPC) goto done;
// Try this class's method lists.
meth = _class_getMethodNoSuper_nolock(cls, sel);
if (meth) {
log_and_fill_cache(cls, cls, meth, sel);
methodPC = method_getImplementation(meth);
goto done;
}
// Try superclass caches and method lists.
curClass = cls;
while ((curClass = curClass->superclass)) {
// Superclass cache.
meth = _cache_getMethod(curClass, sel, _objc_msgForward_impcache);
if (meth) {
if (meth != (Method)1) {
// Found the method in a superclass. Cache it in this class.
log_and_fill_cache(cls, curClass, meth, sel);
methodPC = method_getImplementation(meth);
goto done;
}
else {
// Found a forward:: entry in a superclass.
// Stop searching, but don't cache yet; call method
// resolver for this class first.
break;
}
}
// Superclass method list.
meth = _class_getMethodNoSuper_nolock(curClass, sel);
if (meth) {
log_and_fill_cache(cls, curClass, meth, sel);
methodPC = method_getImplementation(meth);
goto done;
}
}
// No implementation found. Try method resolver once.
if ((behavior & LOOKUP_RESOLVER) && !triedResolver) {
methodListLock.unlock();
_class_resolveMethod(cls, sel, inst);
triedResolver = YES;
goto retry;
}
// No implementation found, and method resolver didn't help.
// Use forwarding.
_cache_addForwardEntry(cls, sel);
methodPC = _objc_msgForward_impcache;
done:
methodListLock.unlock();
out_nolock:
if ((behavior & LOOKUP_NIL) && methodPC == (IMP)_objc_msgForward_impcache) {
return nil;
}
return methodPC;
}
/***********************************************************************
* lookupMethodInClassAndLoadCache.
* Like _class_lookupMethodAndLoadCache, but does not search superclasses.
* Caches and returns objc_msgForward if the method is not found in the class.
**********************************************************************/
IMP lookupMethodInClassAndLoadCache(Class cls, SEL sel)
{
Method meth;
IMP imp;
// fixme this still has the method list vs method cache race
// because it doesn't hold a lock across lookup+cache_fill,
// but it's only used for .cxx_construct/destruct and we assume
// categories don't change them.
// Search cache first.
imp = _cache_getImp(cls, sel);
if (imp) return imp;
// Cache miss. Search method list.
meth = _class_getMethodNoSuper(cls, sel);
if (meth) {
// Hit in method list. Cache it.
_cache_fill(cls, meth, sel);
return method_getImplementation(meth);
} else {
// Miss in method list. Cache objc_msgForward.
_cache_addForwardEntry(cls, sel);
return _objc_msgForward_impcache;
}
}
/***********************************************************************
* _class_getClassForIvar
* Given a class and an ivar that is in it or one of its superclasses,
* find the actual class that defined the ivar.
**********************************************************************/
Class _class_getClassForIvar(Class cls, Ivar ivar)
{
for ( ; cls; cls = cls->superclass) {
if (auto ivars = cls->ivars) {
if (ivar >= &ivars->ivar_list[0] &&
ivar < &ivars->ivar_list[ivars->ivar_count])
{
return cls;
}
}
}
return nil;
}
/***********************************************************************
* class_getVariable. Return the named instance variable.
**********************************************************************/
Ivar _class_getVariable(Class cls, const char *name)
{
for (; cls != Nil; cls = cls->superclass) {
int i;
// Skip class having no ivars
if (!cls->ivars) continue;
for (i = 0; i < cls->ivars->ivar_count; i++) {
// Check this ivar's name. Be careful because the
// compiler generates ivar entries with nil ivar_name
// (e.g. for anonymous bit fields).
old_ivar *ivar = &cls->ivars->ivar_list[i];
if (ivar->ivar_name && 0 == strcmp(name, ivar->ivar_name)) {
return (Ivar)ivar;
}
}
}
// Not found
return nil;
}
old_property *
property_list_nth(const old_property_list *plist, uint32_t i)
{
return (old_property *)(i*plist->entsize + (char *)&plist->first);
}
old_property **
copyPropertyList(old_property_list *plist, unsigned int *outCount)
{
old_property **result = nil;
unsigned int count = 0;
if (plist) {
count = plist->count;
}
if (count > 0) {
unsigned int i;
result = (old_property **)malloc((count+1) * sizeof(old_property *));
for (i = 0; i < count; i++) {
result[i] = property_list_nth(plist, i);
}
result[i] = nil;
}
if (outCount) *outCount = count;
return result;
}
static old_property_list *
nextPropertyList(Class cls, uintptr_t *indexp)
{
old_property_list *result = nil;
classLock.assertLocked();
if (! ((cls->info & CLS_EXT) && cls->ext)) {
// No class ext
result = nil;
} else if (!cls->ext->propertyLists) {
// No property lists
result = nil;
} else if (cls->info & CLS_NO_PROPERTY_ARRAY) {
// Only one property list
if (*indexp == 0) {
result = (old_property_list *)cls->ext->propertyLists;
} else {
result = nil;
}
} else {
// More than one property list
result = cls->ext->propertyLists[*indexp];
}
if (result) {
++*indexp;
return result;
} else {
*indexp = 0;
return nil;
}
}
/***********************************************************************
* class_getIvarLayout
* nil means all-scanned. "" means non-scanned.
**********************************************************************/
const uint8_t *
class_getIvarLayout(Class cls)
{
if (cls && (cls->info & CLS_EXT)) {
return cls->ivar_layout;
} else {
return nil; // conservative scan
}
}
/***********************************************************************
* class_getWeakIvarLayout
* nil means no weak ivars.
**********************************************************************/
const uint8_t *
class_getWeakIvarLayout(Class cls)
{
if (cls && (cls->info & CLS_EXT) && cls->ext) {
return cls->ext->weak_ivar_layout;
} else {
return nil; // no weak ivars
}
}
/***********************************************************************
* class_setIvarLayout
* nil means all-scanned. "" means non-scanned.
**********************************************************************/
void class_setIvarLayout(Class cls, const uint8_t *layout)
{
if (!cls) return;
if (! (cls->info & CLS_EXT)) {
_objc_inform("class '%s' needs to be recompiled", cls->name);
return;
}
// fixme leak
cls->ivar_layout = ustrdupMaybeNil(layout);
}
/***********************************************************************
* class_setWeakIvarLayout
* nil means no weak ivars.
**********************************************************************/
void class_setWeakIvarLayout(Class cls, const uint8_t *layout)
{
if (!cls) return;
mutex_locker_t lock(classLock);
allocateExt(cls);
// fixme leak
cls->ext->weak_ivar_layout = ustrdupMaybeNil(layout);
}
/***********************************************************************
* class_setVersion. Record the specified version with the class.
**********************************************************************/
void class_setVersion(Class cls, int version)
{
if (!cls) return;
cls->version = version;
}
/***********************************************************************
* class_getVersion. Return the version recorded with the class.
**********************************************************************/
int class_getVersion(Class cls)
{
if (!cls) return 0;
return (int)cls->version;
}
/***********************************************************************
* class_getName.
**********************************************************************/
const char *class_getName(Class cls)
{
if (!cls) return "nil";
else return cls->demangledName();
}
/***********************************************************************
* _class_getNonMetaClass.
* Return the ordinary class for this class or metaclass.
* Used by +initialize.
**********************************************************************/
static Class _class_getNonMetaClass(Class cls, id obj)
{
// fixme ick
if (cls->isMetaClass()) {
if (cls->info & CLS_CONSTRUCTING) {
// Class is under construction and isn't in the class_hash,
// so objc_getClass doesn't work.
cls = obj; // fixme this may be nil in some paths
}
else if (strncmp(cls->name, "_%", 2) == 0) {
// Posee's meta's name is smashed and isn't in the class_hash,
// so objc_getClass doesn't work.
const char *baseName = strchr(cls->name, '%'); // get posee's real name
cls = objc_getClass(baseName);
}
else {
cls = objc_getClass(cls->name);
}
ASSERT(cls);
}
return cls;
}
Class class_initialize(Class cls, id inst) {
if (!cls->isInitialized()) {
initializeNonMetaClass (_class_getNonMetaClass(cls, inst));
}
return cls;
}
Cache _class_getCache(Class cls)
{
return cls->cache;
}
void _class_setCache(Class cls, Cache cache)
{
cls->cache = cache;
}
const char *_category_getName(Category cat)
{
return oldcategory(cat)->category_name;
}
const char *_category_getClassName(Category cat)
{
return oldcategory(cat)->class_name;
}
Class _category_getClass(Category cat)
{
return objc_getClass(oldcategory(cat)->class_name);
}
IMP _category_getLoadMethod(Category cat)
{
old_method_list *mlist = oldcategory(cat)->class_methods;
if (mlist) {
return lookupNamedMethodInMethodList(mlist, "load");
} else {
return nil;
}
}
/***********************************************************************
* class_nextMethodList.
* External version of nextMethodList().
*
* This function is not fully thread-safe. A series of calls to
* class_nextMethodList() may fail if methods are added to or removed
* from the class between calls.
* If methods are added between calls to class_nextMethodList(), it may
* return previously-returned method lists again, and may fail to return
* newly-added lists.
* If methods are removed between calls to class_nextMethodList(), it may
* omit surviving method lists or simply crash.
**********************************************************************/
struct objc_method_list *class_nextMethodList(Class cls, void **it)
{
OBJC_WARN_DEPRECATED;
mutex_locker_t lock(methodListLock);
return (struct objc_method_list *) nextMethodList(cls, it);
}
/***********************************************************************
* class_addMethods.
*
* Formerly class_addInstanceMethods ()
**********************************************************************/
void class_addMethods(Class cls, struct objc_method_list *meths)
{
OBJC_WARN_DEPRECATED;
// Add the methods.
{
mutex_locker_t lock(methodListLock);
_objc_insertMethods(cls, (old_method_list *)meths, nil);
}
// Must flush when dynamically adding methods. No need to flush
// all the class method caches. If cls is a meta class, though,
// this will still flush it and any of its sub-meta classes.
flush_caches (cls, NO);
}
/***********************************************************************
* class_removeMethods.
**********************************************************************/
void class_removeMethods(Class cls, struct objc_method_list *meths)
{
OBJC_WARN_DEPRECATED;
// Remove the methods
{
mutex_locker_t lock(methodListLock);
_objc_removeMethods(cls, (old_method_list *)meths);
}
// Must flush when dynamically removing methods. No need to flush
// all the class method caches. If cls is a meta class, though,
// this will still flush it and any of its sub-meta classes.
flush_caches (cls, NO);
}
/***********************************************************************
* lookupNamedMethodInMethodList
* Only called to find +load/-.cxx_construct/-.cxx_destruct methods,
* without fixing up the entire method list.
* The class is not yet in use, so methodListLock is not taken.
**********************************************************************/
IMP lookupNamedMethodInMethodList(old_method_list *mlist, const char *meth_name)
{
old_method *m;
m = meth_name ? _findNamedMethodInList(mlist, meth_name) : nil;
return (m ? m->method_imp : nil);
}
static Method _class_getMethod(Class cls, SEL sel)
{
mutex_locker_t lock(methodListLock);
return (Method)_getMethod(cls, sel);
}
static Method _class_getMethodNoSuper(Class cls, SEL sel)
{
mutex_locker_t lock(methodListLock);
return (Method)_findMethodInClass(cls, sel);
}
static Method _class_getMethodNoSuper_nolock(Class cls, SEL sel)
{
methodListLock.assertLocked();
return (Method)_findMethodInClass(cls, sel);
}
/***********************************************************************
* class_getInstanceMethod. Return the instance method for the
* specified class and selector.
**********************************************************************/
Method class_getInstanceMethod(Class cls, SEL sel)
{
if (!cls || !sel) return nil;
// This deliberately avoids +initialize because it historically did so.
// This implementation is a bit weird because it's the only place that
// wants a Method instead of an IMP.
Method meth;
meth = _cache_getMethod(cls, sel, _objc_msgForward_impcache);
if (meth == (Method)1) {
// Cache contains forward:: . Stop searching.
return nil;
} else if (meth) {
return meth;
}
// Search method lists, try method resolver, etc.
lookUpImpOrForward(nil, sel, cls, LOOKUP_INITIALIZE | LOOKUP_RESOLVER);
meth = _cache_getMethod(cls, sel, _objc_msgForward_impcache);
if (meth == (Method)1) {
// Cache contains forward:: . Stop searching.
return nil;
} else if (meth) {
return meth;
}
return _class_getMethod(cls, sel);
}
BOOL class_conformsToProtocol(Class cls, Protocol *proto_gen)
{
old_protocol *proto = oldprotocol(proto_gen);
if (!cls) return NO;
if (!proto) return NO;
if (cls->ISA()->version >= 3) {
old_protocol_list *list;
for (list = cls->protocols; list != nil; list = list->next) {
int i;
for (i = 0; i < list->count; i++) {
if (list->list[i] == proto) return YES;
if (protocol_conformsToProtocol((Protocol *)list->list[i], proto_gen)) return YES;
}
if (cls->ISA()->version <= 4) break;
}
}
return NO;
}
static NXMapTable * posed_class_hash = nil;
/***********************************************************************
* objc_getOrigClass.
**********************************************************************/
extern "C"
Class _objc_getOrigClass(const char *name)
{
// Look for class among the posers
{
mutex_locker_t lock(classLock);
if (posed_class_hash) {
Class cls = (Class) NXMapGet (posed_class_hash, name);
if (cls) return cls;
}
}
// Not a poser. Do a normal lookup.
Class cls = objc_getClass (name);
if (cls) return cls;
_objc_inform ("class `%s' not linked into application", name);
return nil;
}
Class objc_getOrigClass(const char *name)
{
OBJC_WARN_DEPRECATED;
return _objc_getOrigClass(name);
}
/***********************************************************************
* _objc_addOrigClass. This function is only used from class_poseAs.
* Registers the original class names, before they get obscured by
* posing, so that [super ..] will work correctly from categories
* in posing classes and in categories in classes being posed for.
**********************************************************************/
static void _objc_addOrigClass (Class origClass)
{
mutex_locker_t lock(classLock);
// Create the poser's hash table on first use
if (!posed_class_hash)
{
posed_class_hash = NXCreateMapTable(NXStrValueMapPrototype, 8);
}
// Add the named class iff it is not already there (or collides?)
if (NXMapGet (posed_class_hash, origClass->name) == 0)
NXMapInsert (posed_class_hash, origClass->name, origClass);
}
/***********************************************************************
* change_class_references
* Change classrefs and superclass pointers from original to imposter
* But if copy!=nil, don't change copy->superclass.
* If changeSuperRefs==YES, also change [super message] classrefs.
* Used by class_poseAs and objc_setFutureClass
* classLock must be locked.
**********************************************************************/
void change_class_references(Class imposter,
Class original,
Class copy,
bool changeSuperRefs)
{
header_info *hInfo;
Class clsObject;
NXHashState state;
// Change all subclasses of the original to point to the imposter.
state = NXInitHashState (class_hash);
while (NXNextHashState (class_hash, &state, (void **) &clsObject))
{
while ((clsObject) && (clsObject != imposter) &&
(clsObject != copy))
{
if (clsObject->superclass == original)
{
clsObject->superclass = imposter;
clsObject->ISA()->superclass = imposter->ISA();
// We must flush caches here!
break;
}
clsObject = clsObject->superclass;
}
}
// Replace the original with the imposter in all class refs
// Major loop - process all headers
for (hInfo = FirstHeader; hInfo != nil; hInfo = hInfo->getNext())
{
Class *cls_refs;
size_t refCount;
unsigned int index;
// Fix class refs associated with this header
cls_refs = _getObjcClassRefs(hInfo, &refCount);
if (cls_refs) {
for (index = 0; index < refCount; index += 1) {
if (cls_refs[index] == original) {
cls_refs[index] = imposter;
}
}
}
}
}
/***********************************************************************
* class_poseAs.
*
* !!! class_poseAs () does not currently flush any caches.
**********************************************************************/
Class class_poseAs(Class imposter, Class original)
{
char * imposterNamePtr;
Class copy;
OBJC_WARN_DEPRECATED;
// Trivial case is easy
if (imposter == original)
return imposter;
// Imposter must be an immediate subclass of the original
if (imposter->superclass != original) {
__objc_error(imposter,
"[%s poseAs:%s]: target not immediate superclass",
imposter->name, original->name);
}
// Can't pose when you have instance variables (how could it work?)
if (imposter->ivars) {
__objc_error(imposter,
"[%s poseAs:%s]: %s defines new instance variables",
imposter->name, original->name, imposter->name);
}
// Build a string to use to replace the name of the original class.
#if TARGET_OS_WIN32
# define imposterNamePrefix "_%"
imposterNamePtr = malloc(strlen(original->name) + strlen(imposterNamePrefix) + 1);
strcpy(imposterNamePtr, imposterNamePrefix);
strcat(imposterNamePtr, original->name);
# undef imposterNamePrefix
#else
asprintf(&imposterNamePtr, "_%%%s", original->name);
#endif
// We lock the class hashtable, so we are thread safe with respect to
// calls to objc_getClass (). However, the class names are not
// changed atomically, nor are all of the subclasses updated
// atomically. I have ordered the operations so that you will
// never crash, but you may get inconsistent results....
// Register the original class so that [super ..] knows
// exactly which classes are the "original" classes.
_objc_addOrigClass (original);
_objc_addOrigClass (imposter);
// Copy the imposter, so that the imposter can continue
// its normal life in addition to changing the behavior of
// the original. As a hack we don't bother to copy the metaclass.
// For some reason we modify the original rather than the copy.
copy = (Class)malloc(sizeof(objc_class));
memmove(copy, imposter, sizeof(objc_class));
mutex_locker_t lock(classLock);
// Remove both the imposter and the original class.
NXHashRemove (class_hash, imposter);
NXHashRemove (class_hash, original);
NXHashInsert (class_hash, copy);
// Mark the imposter as such
imposter->setInfo(CLS_POSING);
imposter->ISA()->setInfo(CLS_POSING);
// Change the name of the imposter to that of the original class.
imposter->name = original->name;
imposter->ISA()->name = original->ISA()->name;
// Also copy the version field to avoid archiving problems.
imposter->version = original->version;
// Change classrefs and superclass pointers
// Don't change copy->superclass
// Don't change [super ...] messages
change_class_references(imposter, original, copy, NO);
// Change the name of the original class.
original->name = imposterNamePtr + 1;
original->ISA()->name = imposterNamePtr;
// Restore the imposter and the original class with their new names.
NXHashInsert (class_hash, imposter);
NXHashInsert (class_hash, original);
return imposter;
}
/***********************************************************************
* _objc_flush_caches. Flush the instance and class method caches
* of cls and all its subclasses.
*
* Specifying Nil for the class "all classes."
**********************************************************************/
static void flush_caches(Class target, bool flush_meta)
{
bool collectALot = (target == nil);
NXHashState state;
Class clsObject;
#ifdef OBJC_INSTRUMENTED
unsigned int classesVisited;
unsigned int subclassCount;
#endif
mutex_locker_t lock(classLock);
mutex_locker_t lock2(cacheUpdateLock);
// Leaf classes are fastest because there are no subclass caches to flush.
// fixme instrument
if (target && (target->info & CLS_LEAF)) {
_cache_flush (target);
if (target->ISA() && (target->ISA()->info & CLS_LEAF)) {
_cache_flush (target->ISA());
return; // done
} else {
// Reset target and handle it by one of the methods below.
target = target->ISA();
flush_meta = NO;
// NOT done
}
}
state = NXInitHashState(class_hash);
// Handle nil and root instance class specially: flush all
// instance and class method caches. Nice that this
// loop is linear vs the N-squared loop just below.
if (!target || !target->superclass)
{
#ifdef OBJC_INSTRUMENTED
LinearFlushCachesCount += 1;
classesVisited = 0;
subclassCount = 0;
#endif
// Traverse all classes in the hash table
while (NXNextHashState(class_hash, &state, (void**)&clsObject))
{
Class metaClsObject;
#ifdef OBJC_INSTRUMENTED
classesVisited += 1;
#endif
// Skip class that is known not to be a subclass of this root
// (the isa pointer of any meta class points to the meta class
// of the root).
// NOTE: When is an isa pointer of a hash tabled class ever nil?
metaClsObject = clsObject->ISA();
if (target && metaClsObject && target->ISA() != metaClsObject->ISA()) {
continue;
}
#ifdef OBJC_INSTRUMENTED
subclassCount += 1;
#endif
_cache_flush (clsObject);
if (flush_meta && metaClsObject != nil) {
_cache_flush (metaClsObject);
}
}
#ifdef OBJC_INSTRUMENTED
LinearFlushCachesVisitedCount += classesVisited;
if (classesVisited > MaxLinearFlushCachesVisitedCount)
MaxLinearFlushCachesVisitedCount = classesVisited;
IdealFlushCachesCount += subclassCount;
if (subclassCount > MaxIdealFlushCachesCount)
MaxIdealFlushCachesCount = subclassCount;
#endif
goto done;
}
// Outer loop - flush any cache that could now get a method from
// cls (i.e. the cache associated with cls and any of its subclasses).
#ifdef OBJC_INSTRUMENTED
NonlinearFlushCachesCount += 1;
classesVisited = 0;
subclassCount = 0;
#endif
while (NXNextHashState(class_hash, &state, (void**)&clsObject))
{
Class clsIter;
#ifdef OBJC_INSTRUMENTED
NonlinearFlushCachesClassCount += 1;
#endif
// Inner loop - Process a given class
clsIter = clsObject;
while (clsIter)
{
#ifdef OBJC_INSTRUMENTED
classesVisited += 1;
#endif
// Flush clsObject instance method cache if
// clsObject is a subclass of cls, or is cls itself
// Flush the class method cache if that was asked for
if (clsIter == target)
{
#ifdef OBJC_INSTRUMENTED
subclassCount += 1;
#endif
_cache_flush (clsObject);
if (flush_meta)
_cache_flush (clsObject->ISA());
break;
}
// Flush clsObject class method cache if cls is
// the meta class of clsObject or of one
// of clsObject's superclasses
else if (clsIter->ISA() == target)
{
#ifdef OBJC_INSTRUMENTED
subclassCount += 1;
#endif
_cache_flush (clsObject->ISA());
break;
}
// Move up superclass chain
// else if (clsIter->isInitialized())
clsIter = clsIter->superclass;
// clsIter is not initialized, so its cache
// must be empty. This happens only when
// clsIter == clsObject, because
// superclasses are initialized before
// subclasses, and this loop traverses
// from sub- to super- classes.
// else
// break;
}
}
#ifdef OBJC_INSTRUMENTED
NonlinearFlushCachesVisitedCount += classesVisited;
if (classesVisited > MaxNonlinearFlushCachesVisitedCount)
MaxNonlinearFlushCachesVisitedCount = classesVisited;
IdealFlushCachesCount += subclassCount;
if (subclassCount > MaxIdealFlushCachesCount)
MaxIdealFlushCachesCount = subclassCount;
#endif
done:
if (collectALot) {
_cache_collect(true);
}
}
void _objc_flush_caches(Class target)
{
flush_caches(target, YES);
}
/***********************************************************************
* flush_marked_caches. Flush the method cache of any class marked
* CLS_FLUSH_CACHE (and all subclasses thereof)
* fixme instrument
**********************************************************************/
void flush_marked_caches(void)
{
Class cls;
Class supercls;
NXHashState state;
mutex_locker_t lock(classLock);
mutex_locker_t lock2(cacheUpdateLock);
state = NXInitHashState(class_hash);
while (NXNextHashState(class_hash, &state, (void**)&cls)) {
for (supercls = cls; supercls; supercls = supercls->superclass) {
if (supercls->info & CLS_FLUSH_CACHE) {
_cache_flush(cls);
break;
}
}
for (supercls = cls->ISA(); supercls; supercls = supercls->superclass) {
if (supercls->info & CLS_FLUSH_CACHE) {
_cache_flush(cls->ISA());
break;
}
}
}
state = NXInitHashState(class_hash);
while (NXNextHashState(class_hash, &state, (void**)&cls)) {
if (cls->info & CLS_FLUSH_CACHE) {
cls->clearInfo(CLS_FLUSH_CACHE);
}
if (cls->ISA()->info & CLS_FLUSH_CACHE) {
cls->ISA()->clearInfo(CLS_FLUSH_CACHE);
}
}
}
/***********************************************************************
* get_base_method_list
* Returns the method list containing the class's own methods,
* ignoring any method lists added by categories or class_addMethods.
* Called only by add_class_to_loadable_list.
* Does not hold methodListLock because add_class_to_loadable_list
* does not manipulate in-use classes.
**********************************************************************/
static old_method_list *get_base_method_list(Class cls)
{
old_method_list **ptr;
if (!cls->methodLists) return nil;
if (cls->info & CLS_NO_METHOD_ARRAY) return (old_method_list *)cls->methodLists;
ptr = cls->methodLists;
if (!*ptr || *ptr == END_OF_METHODS_LIST) return nil;
while ( *ptr != 0 && *ptr != END_OF_METHODS_LIST ) { ptr++; }
--ptr;
return *ptr;
}
static IMP _class_getLoadMethod_nocheck(Class cls)
{
old_method_list *mlist;
mlist = get_base_method_list(cls->ISA());
if (mlist) {
return lookupNamedMethodInMethodList (mlist, "load");
}
return nil;
}
bool _class_hasLoadMethod(Class cls)
{
if (cls->ISA()->info & CLS_HAS_LOAD_METHOD) return YES;
return _class_getLoadMethod_nocheck(cls);
}
/***********************************************************************
* objc_class::getLoadMethod
* Returns cls's +load implementation, or nil if it doesn't have one.
**********************************************************************/
IMP objc_class::getLoadMethod()
{
if (ISA()->info & CLS_HAS_LOAD_METHOD) {
return _class_getLoadMethod_nocheck((Class)this);
}
return nil;
}
ptrdiff_t ivar_getOffset(Ivar ivar)
{
return oldivar(ivar)->ivar_offset;
}
const char *ivar_getName(Ivar ivar)
{
return oldivar(ivar)->ivar_name;
}
const char *ivar_getTypeEncoding(Ivar ivar)
{
return oldivar(ivar)->ivar_type;
}
IMP method_getImplementation(Method m)
{
if (!m) return nil;
return oldmethod(m)->method_imp;
}
SEL method_getName(Method m)
{
if (!m) return nil;
return oldmethod(m)->method_name;
}
const char *method_getTypeEncoding(Method m)
{
if (!m) return nil;
return oldmethod(m)->method_types;
}
unsigned int method_getSizeOfArguments(Method m)
{
OBJC_WARN_DEPRECATED;
if (!m) return 0;
return encoding_getSizeOfArguments(method_getTypeEncoding(m));
}
// This function was accidentally un-exported beginning in macOS 10.9.
// As of macOS 10.13 nobody had complained.
/*
unsigned int method_getArgumentInfo(Method m, int arg,
const char **type, int *offset)
{
OBJC_WARN_DEPRECATED;
if (!m) return 0;
return encoding_getArgumentInfo(method_getTypeEncoding(m),
arg, type, offset);
}
*/
spinlock_t impLock;
IMP method_setImplementation(Method m_gen, IMP imp)
{
IMP old;
old_method *m = oldmethod(m_gen);
if (!m) return nil;
if (!imp) return nil;
impLock.lock();
old = m->method_imp;
m->method_imp = imp;
impLock.unlock();
return old;
}
void method_exchangeImplementations(Method m1_gen, Method m2_gen)
{
IMP m1_imp;
old_method *m1 = oldmethod(m1_gen);
old_method *m2 = oldmethod(m2_gen);
if (!m1 || !m2) return;
impLock.lock();
m1_imp = m1->method_imp;
m1->method_imp = m2->method_imp;
m2->method_imp = m1_imp;
impLock.unlock();
}
struct objc_method_description * method_getDescription(Method m)
{
if (!m) return nil;
return (struct objc_method_description *)oldmethod(m);
}
const char *property_getName(objc_property_t prop)
{
return oldproperty(prop)->name;
}
const char *property_getAttributes(objc_property_t prop)
{
return oldproperty(prop)->attributes;
}
objc_property_attribute_t *property_copyAttributeList(objc_property_t prop,
unsigned int *outCount)
{
if (!prop) {
if (outCount) *outCount = 0;
return nil;
}
mutex_locker_t lock(classLock);
return copyPropertyAttributeList(oldproperty(prop)->attributes,outCount);
}
char * property_copyAttributeValue(objc_property_t prop, const char *name)
{
if (!prop || !name || *name == '\0') return nil;
mutex_locker_t lock(classLock);
return copyPropertyAttributeValue(oldproperty(prop)->attributes, name);
}
/***********************************************************************
* class_addMethod
**********************************************************************/
static IMP _class_addMethod(Class cls, SEL name, IMP imp,
const char *types, bool replace)
{
old_method *m;
IMP result = nil;
if (!types) types = "";
mutex_locker_t lock(methodListLock);
if ((m = _findMethodInClass(cls, name))) {
// already exists
// fixme atomic
result = method_getImplementation((Method)m);
if (replace) {
method_setImplementation((Method)m, imp);
}
} else {
// fixme could be faster
old_method_list *mlist =
(old_method_list *)calloc(sizeof(old_method_list), 1);
mlist->obsolete = fixed_up_method_list;
mlist->method_count = 1;
mlist->method_list[0].method_name = name;
mlist->method_list[0].method_types = strdup(types);
mlist->method_list[0].method_imp = imp;
_objc_insertMethods(cls, mlist, nil);
if (!(cls->info & CLS_CONSTRUCTING)) {
flush_caches(cls, NO);
} else {
// in-construction class has no subclasses
flush_cache(cls);
}
result = nil;
}
return result;
}
/***********************************************************************
* class_addMethod
**********************************************************************/
BOOL class_addMethod(Class cls, SEL name, IMP imp, const char *types)
{
IMP old;
if (!cls) return NO;
old = _class_addMethod(cls, name, imp, types, NO);
return !old;
}
/***********************************************************************
* class_replaceMethod
**********************************************************************/
IMP class_replaceMethod(Class cls, SEL name, IMP imp, const char *types)
{
if (!cls) return nil;
return _class_addMethod(cls, name, imp, types, YES);
}
/***********************************************************************
* class_addIvar
**********************************************************************/
BOOL class_addIvar(Class cls, const char *name, size_t size,
uint8_t alignment, const char *type)
{
bool result = YES;
if (!cls) return NO;
if (ISMETA(cls)) return NO;
if (!(cls->info & CLS_CONSTRUCTING)) return NO;
if (!type) type = "";
if (name && 0 == strcmp(name, "")) name = nil;
mutex_locker_t lock(classLock);
// Check for existing ivar with this name
// fixme check superclasses?
if (cls->ivars) {
int i;
for (i = 0; i < cls->ivars->ivar_count; i++) {
if (0 == strcmp(cls->ivars->ivar_list[i].ivar_name, name)) {
result = NO;
break;
}
}
}
if (result) {
old_ivar_list *old = cls->ivars;
size_t oldSize;
int newCount;
old_ivar *ivar;
size_t alignBytes;
size_t misalign;
if (old) {
oldSize = sizeof(old_ivar_list) +
(old->ivar_count - 1) * sizeof(old_ivar);
newCount = 1 + old->ivar_count;
} else {
oldSize = sizeof(old_ivar_list) - sizeof(old_ivar);
newCount = 1;
}
// allocate new ivar list
cls->ivars = (old_ivar_list *)
calloc(oldSize+sizeof(old_ivar), 1);
if (old) memcpy(cls->ivars, old, oldSize);
if (old && malloc_size(old)) free(old);
cls->ivars->ivar_count = newCount;
ivar = &cls->ivars->ivar_list[newCount-1];
// set ivar name and type
ivar->ivar_name = strdup(name);
ivar->ivar_type = strdup(type);
// align if necessary
alignBytes = 1 << alignment;
misalign = cls->instance_size % alignBytes;
if (misalign) cls->instance_size += (long)(alignBytes - misalign);
// set ivar offset and increase instance size
ivar->ivar_offset = (int)cls->instance_size;
cls->instance_size += (long)size;
}
return result;
}
/***********************************************************************
* class_addProtocol
**********************************************************************/
BOOL class_addProtocol(Class cls, Protocol *protocol_gen)
{
old_protocol *protocol = oldprotocol(protocol_gen);
old_protocol_list *plist;
if (!cls) return NO;
if (class_conformsToProtocol(cls, protocol_gen)) return NO;
mutex_locker_t lock(classLock);
// fixme optimize - protocol list doesn't escape?
plist = (old_protocol_list*)calloc(sizeof(old_protocol_list), 1);
plist->count = 1;
plist->list[0] = protocol;
plist->next = cls->protocols;
cls->protocols = plist;
// fixme metaclass?
return YES;
}
/***********************************************************************
* _class_addProperties
* Internal helper to add properties to a class.
* Used by category attachment and class_addProperty()
* Locking: acquires classLock
**********************************************************************/
bool
_class_addProperties(Class cls,
old_property_list *additions)
{
old_property_list *newlist;
if (!(cls->info & CLS_EXT)) return NO;
newlist = (old_property_list *)
memdup(additions, sizeof(*newlist) - sizeof(newlist->first)
+ (additions->entsize * additions->count));
mutex_locker_t lock(classLock);
allocateExt(cls);
if (!cls->ext->propertyLists) {
// cls has no properties - simply use this list
cls->ext->propertyLists = (old_property_list **)newlist;
cls->setInfo(CLS_NO_PROPERTY_ARRAY);
}
else if (cls->info & CLS_NO_PROPERTY_ARRAY) {
// cls has one property list - make a new array
old_property_list **newarray = (old_property_list **)
malloc(3 * sizeof(*newarray));
newarray[0] = newlist;
newarray[1] = (old_property_list *)cls->ext->propertyLists;
newarray[2] = nil;
cls->ext->propertyLists = newarray;
cls->clearInfo(CLS_NO_PROPERTY_ARRAY);
}
else {
// cls has a property array - make a bigger one
old_property_list **newarray;
int count = 0;
while (cls->ext->propertyLists[count]) count++;
newarray = (old_property_list **)
malloc((count+2) * sizeof(*newarray));
newarray[0] = newlist;
memcpy(&newarray[1], &cls->ext->propertyLists[0],
count * sizeof(*newarray));
newarray[count+1] = nil;
free(cls->ext->propertyLists);
cls->ext->propertyLists = newarray;
}
return YES;
}
/***********************************************************************
* class_addProperty
* Adds a property to a class. Returns NO if the proeprty already exists.
* Locking: acquires classLock
**********************************************************************/
static bool
_class_addProperty(Class cls, const char *name,
const objc_property_attribute_t *attrs, unsigned int count,
bool replace)
{
if (!cls) return NO;
if (!name) return NO;
old_property *prop = oldproperty(class_getProperty(cls, name));
if (prop && !replace) {
// already exists, refuse to replace
return NO;
}
else if (prop) {
// replace existing
mutex_locker_t lock(classLock);
try_free(prop->attributes);
prop->attributes = copyPropertyAttributeString(attrs, count);
return YES;
}
else {
// add new
old_property_list proplist;
proplist.entsize = sizeof(old_property);
proplist.count = 1;
proplist.first.name = strdup(name);
proplist.first.attributes = copyPropertyAttributeString(attrs, count);
return _class_addProperties(cls, &proplist);
}
}
BOOL
class_addProperty(Class cls, const char *name,
const objc_property_attribute_t *attrs, unsigned int n)
{
return _class_addProperty(cls, name, attrs, n, NO);
}
void
class_replaceProperty(Class cls, const char *name,
const objc_property_attribute_t *attrs, unsigned int n)
{
_class_addProperty(cls, name, attrs, n, YES);
}
/***********************************************************************
* class_copyProtocolList. Returns a heap block containing the
* protocols implemented by the class, or nil if the class
* implements no protocols. Caller must free the block.
* Does not copy any superclass's protocols.
**********************************************************************/
Protocol * __unsafe_unretained *
class_copyProtocolList(Class cls, unsigned int *outCount)
{
old_protocol_list *plist;
Protocol **result = nil;
unsigned int count = 0;
unsigned int p;
if (!cls) {
if (outCount) *outCount = 0;
return nil;
}
mutex_locker_t lock(classLock);
for (plist = cls->protocols; plist != nil; plist = plist->next) {
count += (int)plist->count;
}
if (count > 0) {
result = (Protocol **)malloc((count+1) * sizeof(Protocol *));
for (p = 0, plist = cls->protocols;
plist != nil;
plist = plist->next)
{
int i;
for (i = 0; i < plist->count; i++) {
result[p++] = (Protocol *)plist->list[i];
}
}
result[p] = nil;
}
if (outCount) *outCount = count;
return result;
}
/***********************************************************************
* class_getProperty. Return the named property.
**********************************************************************/
objc_property_t class_getProperty(Class cls, const char *name)
{
if (!cls || !name) return nil;
mutex_locker_t lock(classLock);
for (; cls; cls = cls->superclass) {
uintptr_t iterator = 0;
old_property_list *plist;
while ((plist = nextPropertyList(cls, &iterator))) {
uint32_t i;
for (i = 0; i < plist->count; i++) {
old_property *p = property_list_nth(plist, i);
if (0 == strcmp(name, p->name)) {
return (objc_property_t)p;
}
}
}
}
return nil;
}
/***********************************************************************
* class_copyPropertyList. Returns a heap block containing the
* properties declared in the class, or nil if the class
* declares no properties. Caller must free the block.
* Does not copy any superclass's properties.
**********************************************************************/
objc_property_t *class_copyPropertyList(Class cls, unsigned int *outCount)
{
old_property_list *plist;
uintptr_t iterator = 0;
old_property **result = nil;
unsigned int count = 0;
unsigned int p, i;
if (!cls) {
if (outCount) *outCount = 0;
return nil;
}
mutex_locker_t lock(classLock);
iterator = 0;
while ((plist = nextPropertyList(cls, &iterator))) {
count += plist->count;
}
if (count > 0) {
result = (old_property **)malloc((count+1) * sizeof(old_property *));
p = 0;
iterator = 0;
while ((plist = nextPropertyList(cls, &iterator))) {
for (i = 0; i < plist->count; i++) {
result[p++] = property_list_nth(plist, i);
}
}
result[p] = nil;
}
if (outCount) *outCount = count;
return (objc_property_t *)result;
}
/***********************************************************************
* class_copyMethodList. Returns a heap block containing the
* methods implemented by the class, or nil if the class
* implements no methods. Caller must free the block.
* Does not copy any superclass's methods.
**********************************************************************/
Method *class_copyMethodList(Class cls, unsigned int *outCount)
{
old_method_list *mlist;
void *iterator = nil;
Method *result = nil;
unsigned int count = 0;
unsigned int m;
if (!cls) {
if (outCount) *outCount = 0;
return nil;
}
mutex_locker_t lock(methodListLock);
iterator = nil;
while ((mlist = nextMethodList(cls, &iterator))) {
count += mlist->method_count;
}
if (count > 0) {
result = (Method *)malloc((count+1) * sizeof(Method));
m = 0;
iterator = nil;
while ((mlist = nextMethodList(cls, &iterator))) {
int i;
for (i = 0; i < mlist->method_count; i++) {
result[m++] = (Method)&mlist->method_list[i];
}
}
result[m] = nil;
}
if (outCount) *outCount = count;
return result;
}
/***********************************************************************
* class_copyIvarList. Returns a heap block containing the
* ivars declared in the class, or nil if the class
* declares no ivars. Caller must free the block.
* Does not copy any superclass's ivars.
**********************************************************************/
Ivar *class_copyIvarList(Class cls, unsigned int *outCount)
{
Ivar *result = nil;
unsigned int count = 0;
int i;
if (!cls) {
if (outCount) *outCount = 0;
return nil;
}
if (cls->ivars) {
count = cls->ivars->ivar_count;
}
if (count > 0) {
result = (Ivar *)malloc((count+1) * sizeof(Ivar));
for (i = 0; i < cls->ivars->ivar_count; i++) {
result[i] = (Ivar)&cls->ivars->ivar_list[i];
}
result[i] = nil;
}
if (outCount) *outCount = count;
return result;
}
/***********************************************************************
* objc_allocateClass.
**********************************************************************/
void set_superclass(Class cls, Class supercls, bool cls_is_new)
{
Class meta = cls->ISA();
if (supercls) {
cls->superclass = supercls;
meta->superclass = supercls->ISA();
meta->initIsa(supercls->ISA()->ISA());
// Propagate C++ cdtors from superclass.
if (supercls->info & CLS_HAS_CXX_STRUCTORS) {
if (cls_is_new) cls->info |= CLS_HAS_CXX_STRUCTORS;
else cls->setInfo(CLS_HAS_CXX_STRUCTORS);
}
// Superclass is no longer a leaf for cache flushing
if (supercls->info & CLS_LEAF) {
supercls->clearInfo(CLS_LEAF);
supercls->ISA()->clearInfo(CLS_LEAF);
}
} else {
cls->superclass = Nil; // superclass of root class is nil
meta->superclass = cls; // superclass of root metaclass is root class
meta->initIsa(meta); // metaclass of root metaclass is root metaclass
// Root class is never a leaf for cache flushing, because the
// root metaclass is a subclass. (This could be optimized, but
// is too uncommon to bother.)
cls->clearInfo(CLS_LEAF);
meta->clearInfo(CLS_LEAF);
}
}
// &UnsetLayout is the default ivar layout during class construction
static const uint8_t UnsetLayout = 0;
Class objc_initializeClassPair(Class supercls, const char *name, Class cls, Class meta)
{
// Connect to superclasses and metaclasses
cls->initIsa(meta);
set_superclass(cls, supercls, YES);
// Set basic info
cls->name = strdup(name);
meta->name = strdup(name);
cls->version = 0;
meta->version = 7;
cls->info = CLS_CLASS | CLS_CONSTRUCTING | CLS_EXT | CLS_LEAF;
meta->info = CLS_META | CLS_CONSTRUCTING | CLS_EXT | CLS_LEAF;
// Set instance size based on superclass.
if (supercls) {
cls->instance_size = supercls->instance_size;
meta->instance_size = supercls->ISA()->instance_size;
} else {
cls->instance_size = sizeof(Class); // just an isa
meta->instance_size = sizeof(objc_class);
}
// No ivars. No methods. Empty cache. No protocols. No layout. Empty ext.
cls->ivars = nil;
cls->methodLists = nil;
cls->cache = (Cache)&_objc_empty_cache;
cls->protocols = nil;
cls->ivar_layout = &UnsetLayout;
cls->ext = nil;
allocateExt(cls);
cls->ext->weak_ivar_layout = &UnsetLayout;
meta->ivars = nil;
meta->methodLists = nil;
meta->cache = (Cache)&_objc_empty_cache;
meta->protocols = nil;
meta->ext = nil;
return cls;
}
Class objc_allocateClassPair(Class supercls, const char *name,
size_t extraBytes)
{
Class cls, meta;
if (objc_getClass(name)) return nil;
// fixme reserve class name against simultaneous allocation
if (supercls && (supercls->info & CLS_CONSTRUCTING)) {
// Can't make subclass of an in-construction class
return nil;
}
// Allocate new classes.
if (supercls) {
cls = _calloc_class(supercls->ISA()->alignedInstanceSize() + extraBytes);
meta = _calloc_class(supercls->ISA()->ISA()->alignedInstanceSize() + extraBytes);
} else {
cls = _calloc_class(sizeof(objc_class) + extraBytes);
meta = _calloc_class(sizeof(objc_class) + extraBytes);
}
objc_initializeClassPair(supercls, name, cls, meta);
return cls;
}
void objc_registerClassPair(Class cls)
{
if ((cls->info & CLS_CONSTRUCTED) ||
(cls->ISA()->info & CLS_CONSTRUCTED))
{
_objc_inform("objc_registerClassPair: class '%s' was already "
"registered!", cls->name);
return;
}
if (!(cls->info & CLS_CONSTRUCTING) ||
!(cls->ISA()->info & CLS_CONSTRUCTING))
{
_objc_inform("objc_registerClassPair: class '%s' was not "
"allocated with objc_allocateClassPair!", cls->name);
return;
}
if (ISMETA(cls)) {
_objc_inform("objc_registerClassPair: class '%s' is a metaclass, "
"not a class!", cls->name);
return;
}
mutex_locker_t lock(classLock);
// Clear "under construction" bit, set "done constructing" bit
cls->info &= ~CLS_CONSTRUCTING;
cls->ISA()->info &= ~CLS_CONSTRUCTING;
cls->info |= CLS_CONSTRUCTED;
cls->ISA()->info |= CLS_CONSTRUCTED;
NXHashInsertIfAbsent(class_hash, cls);
}
Class objc_duplicateClass(Class original, const char *name, size_t extraBytes)
{
unsigned int count, i;
old_method **originalMethods;
old_method_list *duplicateMethods;
// Don't use sizeof(objc_class) here because
// instance_size has historically contained two extra words,
// and instance_size is what objc_getIndexedIvars() actually uses.
Class duplicate =
_calloc_class(original->ISA()->alignedInstanceSize() + extraBytes);
duplicate->initIsa(original->ISA());
duplicate->superclass = original->superclass;
duplicate->name = strdup(name);
duplicate->version = original->version;
duplicate->info = original->info & (CLS_CLASS|CLS_META|CLS_INITIALIZED|CLS_JAVA_HYBRID|CLS_JAVA_CLASS|CLS_HAS_CXX_STRUCTORS|CLS_HAS_LOAD_METHOD);
duplicate->instance_size = original->instance_size;
duplicate->ivars = original->ivars;
// methodLists handled below
duplicate->cache = (Cache)&_objc_empty_cache;
duplicate->protocols = original->protocols;
if (original->info & CLS_EXT) {
duplicate->info |= original->info & (CLS_EXT|CLS_NO_PROPERTY_ARRAY);
duplicate->ivar_layout = original->ivar_layout;
if (original->ext) {
duplicate->ext = (old_class_ext *)malloc(original->ext->size);
memcpy(duplicate->ext, original->ext, original->ext->size);
} else {
duplicate->ext = nil;
}
}
// Method lists are deep-copied so they can be stomped.
originalMethods = (old_method **)class_copyMethodList(original, &count);
if (originalMethods) {
duplicateMethods = (old_method_list *)
calloc(sizeof(old_method_list) +
(count-1)*sizeof(old_method), 1);
duplicateMethods->obsolete = fixed_up_method_list;
duplicateMethods->method_count = count;
for (i = 0; i < count; i++) {
duplicateMethods->method_list[i] = *(originalMethods[i]);
}
duplicate->methodLists = (old_method_list **)duplicateMethods;
duplicate->info |= CLS_NO_METHOD_ARRAY;
free(originalMethods);
}
mutex_locker_t lock(classLock);
NXHashInsert(class_hash, duplicate);
return duplicate;
}
void objc_disposeClassPair(Class cls)
{
if (!(cls->info & (CLS_CONSTRUCTED|CLS_CONSTRUCTING)) ||
!(cls->ISA()->info & (CLS_CONSTRUCTED|CLS_CONSTRUCTING)))
{
// class not allocated with objc_allocateClassPair
// disposing still-unregistered class is OK!
_objc_inform("objc_disposeClassPair: class '%s' was not "
"allocated with objc_allocateClassPair!", cls->name);
return;
}
if (ISMETA(cls)) {
_objc_inform("objc_disposeClassPair: class '%s' is a metaclass, "
"not a class!", cls->name);
return;
}
mutex_locker_t lock(classLock);
NXHashRemove(class_hash, cls);
unload_class(cls->ISA());
unload_class(cls);
}
/***********************************************************************
* objc_constructInstance
* Creates an instance of `cls` at the location pointed to by `bytes`.
* `bytes` must point to at least class_getInstanceSize(cls) bytes of
* well-aligned zero-filled memory.
* The new object's isa is set. Any C++ constructors are called.
* Returns `bytes` if successful. Returns nil if `cls` or `bytes` is
* nil, or if C++ constructors fail.
**********************************************************************/
id
objc_constructInstance(Class cls, void *bytes)
{
if (!cls || !bytes) return nil;
id obj = (id)bytes;
obj->initIsa(cls);
if (cls->hasCxxCtor()) {
return object_cxxConstructFromClass(obj, cls, OBJECT_CONSTRUCT_NONE);
} else {
return obj;
}
}
/***********************************************************************
* _class_createInstanceFromZone. Allocate an instance of the
* specified class with the specified number of bytes for indexed
* variables, in the specified zone. The isa field is set to the
* class, C++ default constructors are called, and all other fields are zeroed.
**********************************************************************/
id
_class_createInstanceFromZone(Class cls, size_t extraBytes, void *zone)
{
void *bytes;
size_t size;
// Can't create something for nothing
if (!cls) return nil;
// Allocate and initialize
size = cls->alignedInstanceSize() + extraBytes;
// CF requires all objects be at least 16 bytes.
if (size < 16) size = 16;
if (zone) {
bytes = malloc_zone_calloc((malloc_zone_t *)zone, 1, size);
} else {
bytes = calloc(1, size);
}
return objc_constructInstance(cls, bytes);
}
/***********************************************************************
* _class_createInstance. Allocate an instance of the specified
* class with the specified number of bytes for indexed variables, in
* the default zone, using _class_createInstanceFromZone.
**********************************************************************/
static id _class_createInstance(Class cls, size_t extraBytes)
{
return _class_createInstanceFromZone (cls, extraBytes, nil);
}
static id _object_copyFromZone(id oldObj, size_t extraBytes, void *zone)
{
id obj;
size_t size;
if (!oldObj) return nil;
obj = (*_zoneAlloc)(oldObj->ISA(), extraBytes, zone);
size = oldObj->ISA()->alignedInstanceSize() + extraBytes;
// fixme need C++ copy constructor
memmove(obj, oldObj, size);
fixupCopiedIvars(obj, oldObj);
return obj;
}
/***********************************************************************
* objc_destructInstance
* Destroys an instance without freeing memory.
* Calls C++ destructors.
* Removes associative references.
* Returns `obj`. Does nothing if `obj` is nil.
* CoreFoundation and other clients do call this under GC.
**********************************************************************/
void *objc_destructInstance(id obj)
{
if (obj) {
Class isa = obj->getIsa();
if (isa->hasCxxDtor()) {
object_cxxDestruct(obj);
}
if (isa->instancesHaveAssociatedObjects()) {
#ifdef DARLING
_object_remove_assocations(obj,false);
#else
_object_remove_assocations(obj);
#endif
}
objc_clear_deallocating(obj);
}
return obj;
}
static id
_object_dispose(id anObject)
{
if (anObject==nil) return nil;
objc_destructInstance(anObject);
anObject->initIsa(_objc_getFreedObjectClass ());
free(anObject);
return nil;
}
static id _object_copy(id oldObj, size_t extraBytes)
{
void *z = malloc_zone_from_ptr(oldObj);
return _object_copyFromZone(oldObj, extraBytes,
z ? z : malloc_default_zone());
}
static id _object_reallocFromZone(id anObject, size_t nBytes, void *zone)
{
id newObject;
Class tmp;
if (anObject == nil)
__objc_error(nil, "reallocating nil object");
if (anObject->ISA() == _objc_getFreedObjectClass ())
__objc_error(anObject, "reallocating freed object");
if (nBytes < anObject->ISA()->alignedInstanceSize())
__objc_error(anObject, "(%s, %zu) requested size too small",
object_getClassName(anObject), nBytes);
// fixme need C++ copy constructor
// fixme GC copy
// Make sure not to modify space that has been declared free
tmp = anObject->ISA();
anObject->initIsa(_objc_getFreedObjectClass ());
newObject = (id)malloc_zone_realloc((malloc_zone_t *)zone, anObject, nBytes);
if (newObject) {
newObject->initIsa(tmp);
} else {
// realloc failed, anObject is still alive
anObject->initIsa(tmp);
}
return newObject;
}
static id _object_realloc(id anObject, size_t nBytes)
{
void *z = malloc_zone_from_ptr(anObject);
return _object_reallocFromZone(anObject,
nBytes,
z ? z : malloc_default_zone());
}
id (*_alloc)(Class, size_t) = _class_createInstance;
id (*_copy)(id, size_t) = _object_copy;
id (*_realloc)(id, size_t) = _object_realloc;
id (*_dealloc)(id) = _object_dispose;
id (*_zoneAlloc)(Class, size_t, void *) = _class_createInstanceFromZone;
id (*_zoneCopy)(id, size_t, void *) = _object_copyFromZone;
id (*_zoneRealloc)(id, size_t, void *) = _object_reallocFromZone;
void (*_error)(id, const char *, va_list) = _objc_error;
id class_createInstance(Class cls, size_t extraBytes)
{
return (*_alloc)(cls, extraBytes);
}
id class_createInstanceFromZone(Class cls, size_t extraBytes, void *z)
{
OBJC_WARN_DEPRECATED;
return (*_zoneAlloc)(cls, extraBytes, z);
}
id
_objc_rootAllocWithZone(Class cls, malloc_zone_t *zone)
{
id obj;
if (fastpath(!zone)) {
obj = class_createInstance(cls, 0);
} else {
obj = class_createInstanceFromZone(cls, 0, zone);
}
if (slowpath(!obj)) obj = _objc_callBadAllocHandler(cls);
return obj;
}
unsigned class_createInstances(Class cls, size_t extraBytes,
id *results, unsigned num_requested)
{
if (_alloc == &_class_createInstance) {
return _class_createInstancesFromZone(cls, extraBytes, nil,
results, num_requested);
} else {
// _alloc in use, which isn't understood by the batch allocator
return 0;
}
}
id object_copy(id obj, size_t extraBytes)
{
return (*_copy)(obj, extraBytes);
}
id object_copyFromZone(id obj, size_t extraBytes, void *z)
{
OBJC_WARN_DEPRECATED;
return (*_zoneCopy)(obj, extraBytes, z);
}
id object_dispose(id obj)
{
return (*_dealloc)(obj);
}
id object_realloc(id obj, size_t nBytes)
{
OBJC_WARN_DEPRECATED;
return (*_realloc)(obj, nBytes);
}
id object_reallocFromZone(id obj, size_t nBytes, void *z)
{
OBJC_WARN_DEPRECATED;
return (*_zoneRealloc)(obj, nBytes, z);
}
/***********************************************************************
* object_getIndexedIvars.
**********************************************************************/
void *object_getIndexedIvars(id obj)
{
// ivars are tacked onto the end of the object
if (obj->isTaggedPointerOrNil()) return nil;
return ((char *) obj) + obj->ISA()->alignedInstanceSize();
}
// ProKit SPI
Class class_setSuperclass(Class cls, Class newSuper)
{
Class oldSuper = cls->superclass;
set_superclass(cls, newSuper, NO);
flush_caches(cls, YES);
return oldSuper;
}
#endif
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